Duplex die head



Dec. 13, 1949 J. H. STEITRNBERGH DUPLEX DIE HEAD 3 Sheets-Sheet 1 Filed Sept. 9, 1948 TIEIi.E:|.

INVENTOR J2me; #E/PVEV Sre'mvesmu ATTORNEY 1949 J. H. STERNBERGH 2,491,453

DUPLEX DIE HEAD Filed Sept. 9, 1948' s Sheets-Sheet a T7 31 INVENTOR James l/snwsv srseuasnqw v ,2 -57 /Z//Z7 I75 ATTORNEY Patented Dec. 13, 1949 DUPLEX ms HEAD James Hervey Sternbergh', Reading, Pa.; Berks County Trust Company executor of said James Hervey Sternbergh, deceased Application September 9, 1948, Serial No. 48,345

17 Claims. (Cl. -96) This invention relates to improvements in die heads for chasing threads on pipe, and has for a principal object the provision of a die head having a set of chasers for one range of sizes oi pipe and a second set of chasers for another range of sizes of pipe, the chasers of one of said sets being angularly displaced from the chasers of the other set.

Another object of the invention is the provision in a die head of one set of thread chasers for one range of sizes of pipe, and a second set of thread chasers for another range of sizes of pipe, the provision of a cam ring for the chasers in said first mentioned set, and a second cam ring for said second set of chasers, a pawl and a rack for fixedly setting said first ring for the several pipe sizes within its range, and a second rack adapted to be brought into cooperative relation with said pawl for fixedly setting said second ring for the several pipe sizes within its range, and means for disengaging one of said pawls from its rack as the other is moved into the range of its rack.

Other objects and advantages of the invention will be apparent to those skilled in the art upon a study of the following specification and the accompanying drawings.

Referring to the drawings which are given by of example to illustrate the invention:

Figure 1 is a front elevation of my improved die head;

Figure 2 is a rear elevation of the die head showing the cross-head carrying cut-off and chamiering tools;

Figure 3 is a side elevation of the die head as seen from the left side of Figure 1 or the right side of Figure 2;

Figure 4 is a front elevation of the die head with the front plate removed and portions thereof in section to show details of the two cam rings and the chasers controlled by each;

Figure 5 is a perspective view of chaser elements;

Figure 6 is a sectional View taken along the lines B6 of Figure 4;

Figure 7 is a sectional elevational view taken along the lines 1-! of Figure 4; V

Figure 8 is a fragmentary front view showing the pawl engaging the rack controlling setting of the chasers of one of said sets;

Figure 9 is similar to Figure 8 except that the front earn ring is being moved to set the other chasers of the other set, and showing how the pawl is automatically disengaged from the other one of the 2 rack, thereby facilitating the setting of the chasers of the other set;

Figure 10 is a plan view looking down on the cam rings from above and showing the relation of the racks to the single pawl, and showing other details; and

Figure 11 is a sectional view showing the automatic release mechanism for releasing the pawl, the lever, and the chasers when the proper length of thread has been formed.

Referring first to Figures 1 to 3 inclusive, the die head body in has formed integral therewith a base I l which is generally in the form of a pan, and formed integral with the pan II is a rectangular sub-base l2. An opening l3 extends through the pan and sub-base. Spaced slides l4 and I5 may extend downwardly from the subbase l2.

A three-way valve I6 is supported on a straight nipple i1, and is provided with an operating handle IS. A curved nipple I9 is connected to the valve [3 and it extends downwardly and inwardly as seen in Figure 3 to deliver oil to the cut-ofi tool to be presently described. The valve also has connected thereto a flexible conduit 20 which is, in turn, connected to a source of oil under pressure.

Referring now to Figure '7, the nipple I! engages a threaded hole formed in a boss 2! formed on the body l0, and communicates with a cavity 22 formed in the body l0.

. The body has an annular rim 23 formed thereon and in alignment therewith is a boss portion 24 which has an extension 25 which forms a loeating boss for a counterbore 28 formed in one end of an annulus 26. The annulus 26 is secured to the body In by means of cap screws, one of which is shown at 21.

The annulus 26 has a counterbore 29 formed in the other end thereof to receive a die spacer and oil ring member 30. The annulus 26 also has slots 3| and 32 in vertical alignment (Figure 4) and slots 33 and 34 in horizontal alignment so that these slots are spaced apart therein.

The annulus 26 also has formed therein slots 35, 36, 37 and 38. These slots are also 90 apart, and they are angularly displaced with respect to the first mentioned slots.

Reciprocally carried in the slots 3|, 32, 33, and 34 are thread chasing tools 39, 40, 4!, and 42 respectively, and reciprocally carried in the slots 35, 36, 31, and 38, are chasing tools 43, 44, 45, and 46 respectively.

In Figure 5, I show one of the chasing tools. This tool is designated by the numeral 39, and

it is identical in shape with the others in that set, namely 4G, 4!, and 42. It consists of a main body having thread forming cutters 4'] which terminate in a chamfered face 48. The upper part has a portion cut away, leaving a shank portion 49, the upper end 50 of which is curved. Spaced apart from the surface 59 is an arcuate slot 55, both faces of which are curved about radii having a common center with the center about which the surface 50 is formed. The cutter portions 4! on the several tools are such that they operate to form a continuous thread on the. work.

The chasing tools 43 to 46inclusive in the other set are similar to the tool v:shown in Figure with the exception that the curved groove 5| is replaced by a curved groove to fit the cams in the cam plate which controls them, as will presently be described. Also the curved end 50-, and the chamfered face is oppositely disposed with respect to the position of the face 48.

The annulus 26 has a central bore 52 which is in. alignment with acentralbore 53 formed in the body l0. Italso has a fiat surface 54 (Figurefl l) formed. thereon and one edge of this surface has an undercut 55 to form a locating shouldy r.

A bracket 5e, secured on the annulus 26 by means of screws" 51, has a depending portion 58 which engages said locating shoulder and is steadied thereby, The bracket'carries an upright lug 59 whichextends rearwardly, as seen in Figured, and carries ontheface thereof bufier material 60. This lug forms a stop for the cam plate 6 l, as will now'be described] The bracket 'tifi alsdhas formed thereon an upright lug 6.2 which 'clarries'fon the face thereof buffer material 63. This lug extends forwardly in the path of and forms a stop for the camplate 54., The cam plate 6i carries four cams, one

{for each of the chasing tools 43, 44, 4.5 and 4",

one of these being shown, by .the numeral 65 and another by the numeral 65a. Sinceall of these are identical a detailed description of only 1 1 and 2".

one of them is deemed 'sufficient.' Consequently thejcam 65c'wi1lbe described in detail.

The cai n 65a includes an overhangin g boundary web BE Which j ins a,radial web fil. The cam 68", is spaced apart and parallel to the web 5 6, and a groove, 69 'therebetween is adapted to accommodate the web 59a formed on the chaser, so that the surfaces 5| engage theicam, and the curved end surface 59"on the, chaser engages: the overhangingi web '66.

The cam plate'fil hasan interiorbore 10 which forms a working fit on the annulus 26. A spring ll has one end secured to the cam plate Bl by "means 'ofa' screw '12 and has its" other end securedto the base I] by means'ofascrew 13. A second spring '14 has one end secured to the cam plate 6| by meansof a screw 15 and the other end issecured tothe base I I by screwl6.

It will'be noted from Figure lthat'these springs are inclined to the; right and therefore they constantly'urge the barn platefi l' a counterclockwise direction and normallyihold-the web fi'l in contact with "the "tuner material on the lug 59. scram/mg the campfire El in a clockwise direction, a rod 1'! has a'threadedend 18.} This threaded endeirtends downwardly andfengages a tapped hole formed in the cam plate 6!, and thusthe rodll forms a handle tofbe'used in setting one set o'f'ohasersfordifierent sizes of pipes. As the cam plateis rotated in a clockwi se direction by means of thehandlefl'l the cam 68 which engages the "slot 5! in 'the Chasers moves them inwardly (radially) and thus these chasers are set to thread different sizes of pipe.

In order to set the chasers for definite sizes of pipe a sector is secured to the cam plate 6! by means of screws 19. The sector 80 intermediate the space between the screws 19 is thicker radially and is provided with a series of notches M. The sector 89 may be seen in a plan view in Figure 10, and it will be noted that the notches 8| indicate pipe sizes as follows: 1", These settings are effected when the notch 8|, indicating the desired size of pipe, is engagedby a pawl 82 which will presently be. described.

Thejsecond, can}; plate 64 has an interior bore 83 which forms a working fit on the annulus 26, and this cam plate has a cam for each of the chasing tools 39, 49, 4| and 42. It has been pointed out above that one set of chasers has the threads 41 and clearance 46 reversed so that the cam groove therein extends forwardly, as viewed in Figure 4, instead'of rearwardly, as was the case for the chasers 43, 44, 45 and 46. The cams for the chasers 39,40, Hand 42 are identical, and it is therefore believed that only one of them need be described in detail.

Each cam consists ofan overhanging web 84, and a caming web 85 parallel thereto and in spaced apart relation therewith. Between the webs 84, 35 is a camgroove 86. The portion 50a on the corresponding chaser-engages the groove 85, and the end surface 50 engages the inner face of the web 84 (Figures 4 and '7).

Referring now to Figure 4, the web 84 joins and has formed integral therewith aradial Web 81, and the radial web 81 of the corresponding cam which controlsthe chasei 39 normally engages the buif er material 63 carried on the lug a screw 94, and-it has'a' loop which engages a hole-in the corresponding web 8'1 of the cam for moving the chaser 4|;-

The cam plate 64 has a handle 96 which may consist o'fa rodwhich-threadedly engages a tapped holein the cam plate-64 similar to the mounting of the handle 11 described above. The cam plate 64 has secured thereto by means of screws 91 a sector 98. The mid portion of the sector 98 between the screws 9-! is somewhat thicker andeit is. provided with notches 99 for indicating. definite-pipe. sizesso that the opera-- tor, may set the chasers 39,145.; Hand 42 for pipe sizes of /2. and 3A1, as-indicated in Figure 10. The operator, bymoving the handle 93 in a clockwise direction, causes the chasing tools 39, 49, 41 and 42 to movetoward the center-of the opening 52 and in the present arrangement the settings arefor /2 and A" pipe. The pawl 82 above described isof sufficient width that it may engage either the notches 8| in the sector 80 or the notches 99 in the sector es.

I Referring to Figure 10, it will be noted that the pawl is in engagement with the notch in the sector 80 which indicates a setting of the chasers 43, 44, 45 and 46 for threading lt" pipe,

Now, supposethe operator grasps the handle Eli-and "rotates the cam plate 64-to make a setting for pipe, for example, the following occurs: As he rotates the cam plate 64 in a clockwise direction the leading screw 91 which screws the sector 98 to the cam plate engages the pawl 82 and cams it upwardly, thereby disengaging it from the notch 8| representing the 1 /2 setting, and this allows the cam plate 6I to rotate in a counterclockwise direction under the urge of its springs TI and 14, and when the web 61 encounters the buffer material 60 on the lug 59 the cam plate BI is arrested in this position. As

the operator continues to move the cam plate 64 in a clockwise direction it reaches a point where the pawl 82 engages the notch 99, which is labeled and he has the setting for A" pipe.

A bracket I09 secured on the body I is provided with spaced lugs [III and I02 to receive an adjustable stud I03 on which a lever I04 having a handle portion I is pivotally mounted on a pin I3I which passes through the lever I04 and an eye on the stud I03. The pawl 82 is pivotally mounted. on a pin I06 carried by the lever I04. A hexagonal'nut I 01 which threadedly engages corresponding threads formed on the stud I03 is positioned between the lugs IOI and I02 and may be operated for advancing or retracting the stud in the lugs to effect a fine adjustment of the position of the pawl 82 in order to accurately position the chasers in accordance with whether the threads on the work shall be exactly the sizes indicated by the scale graduations or whether the threads shall be larger or smaller than said sizes. A look nut I98 threadedly engages the stud I03 and is provided for locking the stud and maintaining any desired adjustment.

The automatic release mechanism for the pawl 82 and the lever I04, and consequently for the chasers, comprises a plunger I 09 slidable in a sleeve I I0 mounted on a radial bore in the body I 0 and an aligned bore in a boss III on the bracket I00. Suitable means are provided for securing the sleeve III] and for preventing rotation of the plunger I09. For example, a set screw II2 extends through the boss III, the sleeve H0 and engages a, key way formed in the plunger I09. The plunger I09 has an upper portion I I3 formed with a central bore within which is secured a stem I I4 and surrounded by a coiled spring I I5 mounted between the base of the bore and an annular shoulder I I6 on the sleeve I I0. The spring II 5 biases the plunger I 09 upwardly so that when the plunger is released, a stud I I1 carried thereby engages and operates the lever I05 to release the pawl 92 and permit the springs II and 14 to retract the chasers 39, 40, M and 42, if they are the ones in use; or to permit the springs 88 and 93 to retract the chasers 43, 44, 45 and 46, if they are the ones in use.

As shown in Figure 11, the stud H1 is moved transversely of the plunger I09 to and from an operative position relative to the lever I05, and a ball detent II8 is provided for holding the stud in either an operative or a non-operative position.

The stem 4 on its lower end is enlarged and carries a cross-pin pivotally supporting a work engaging finger I I 9 which extends into the bore 53 of thedie head. The finger I I9 has a stepped face I20 suitably formed to be engaged by the end of any size pipe within the capacity of the die head for causing the retraction of the chasers when the standard length of thread upon a piece of pipe is completed. A leaf spring I2I biases the finger about its fulcrum I22 to the work engaging position and, when the plunger I09 is depressed, into engagement with a locking latch or pin I23 mounted in the die head body In and extending through a slot I24 in the plunger, and engages a shoulder I25 on the finger I I 9 for looking the plunger I09 in the depressed position. In operation the plunger I09 is depressed and locked by the engagement of the locking pin I23 with the finger II9. Either the cam plate 6| or the cam plate 64 is rotatably adjusted to a setting cutting threads on the size of pipe being worked upon and is locked in such position by the engagement of the pawl 82 with the corresponding notch in the sector or 98. When the plunger is so depressed and locked the stud H1 is beneath the handle of the lever I05. When the proper length of thread has been cut the end of the pipe acting on the finger II9 disengages the latter from the pin I23 whereupon the plunger I09 is raised and is moved radially outwardl by the spring II5. The stud II1 carried by the plunger engages and raises the lever I05, thereby moving the pawl 82 out of engagement with the notch in the member or the member 98, and the springs H and 14 cause the cam plate 6| to return to its normal position if the chasers being used are the chasers 43, 44, 45 and 46; or

1 the springs 88 and 93 cause the cam plate 64 to return to its normal position if the chasers 99, 40, 4| and 42 are used in chasing these threads. Each cam plate, when returning to its normal position, Withdraws the chasers associated with it from the cutting zone.

A post I26 has a shank which threadedly engages a threaded hole in the plate 64, and consequently the post extends radially from the surface of the plate. A threaded hole formed in the post is engaged by threads formed on the shank I21 of a screw which has a disc-like head H8. The threaded shank I21 also carries a lock nut I29, the purpose of which will be presently described.

The sector 98 has a lateral slot I30 formed therein and the disc-like head I28 forms a. working fit with this slot. Now, for obtaining accurate adjustments of the cam plate 64 so that the settings, when either of the notches 99 is engaged by the pawl 82, the lock nut I29 may be loosened and the disc head I28 may be rotated in either direction, after the screws 91 have been slackened, until the desired adjustment i obtained. After this adjustment is obtained the lock nut I29 may again be tightened to retain the adjustment. and then the screws 91 may be tightened to hold the sector 98 in positive engagement with the cam plate 64. A closure plate I45 which has a central hole I46 therein which matches the bore 52 and which has a bevel I41 formed thereon is secured to the annulus 26 by means of screws I48.

On the rear face of the body I9 is provided a web I32 which forms a guide way. Facing the Web I32 in spaced relation thereto is a short guide web I33, and in alignment with this guide and spaced apart from it is a second guide web I 34. A portion of the web I32 and the web I 33 form ways for a V-block I35, and another portion of the web I32 and the web I34 form ways for a V-block I36. The V-block I35 is provided with a left hand nut which engages a section of left hand thread I31 on the screw shaft I39, and the V-block I36 has a right hand nut I 39 which engages a right hand threaded section I40 of the screw shaft I38. The shaft I38 is provided with a bearing MI and secured on the end of the shaft is a handle I42 which when rotated in one direction moves the V-blocks toward each other, and

when rotated in the opposite; dl'rectionit moves upon or damage the release finger H9 or cause it to release the plunger 409, and-therebyretract the chasers before a full lengthof thread has been out. It is also recommended that in chamfering the outer edges of the pipe end s,

the out should be substantially as deep as the root of a thread. I I I II I Although I have herein-shown and described by way of example'one embodiment of theinvention, it is obvious that many changes may be made in thearrang'ements herein" shown and described without departing from the'spirit of the invention.

What is claimed is:

1. In a die head, a body, a set of chasersmovably supported thereon, a member rotatably carried on said body for moving said chasers into and out of operative positions, a second set of chasers movably supported in said body, a second member rotatably carried on said'body for moving said last chas'ers into and out of operative positions, a first notched sector mounted on said first movable member, a second notched sector mounted on said second movable member, a pawl carried on said body and comm'on to'the notches in both said sectors, whereby 'the'chaseis of either of said sets may be set and locked in operative positions by the engagement of said pawl with a notch in either of said sectors.

2. In a die head, a body, a set of chasers movably supported therein, a member rotatably carried on said body and interconnected with said chasers for moving them into and out of operative positions, a s'econd'setof chasers movably supported in said body, a'se condmemberrotatably carried on said body and interconnected with said last chasers for moving them into and out of operative positions; a first sector mounted on said first movable member and havingnotches formed therein, a second sector mounted on said second movable member and having notches formed therein, a pawl carried on said body and common to the notches in both said sectors, whereby either of said sets of chasersmay be set and locked in predetermined operative positions by the engagement of said pawl with anotch in either of said sectors. I

3. A die head according to claim 2, in'which one of said sectors is in advance of the other so that collectively said notches are inseries.

4. In a die head, a body, a set of chase'rs movabl supported therein; a member rotatably car'- ried on said body and interconnected with "said chasers for moving them into and out of'operae time positions, a second set of chasersmovably supported in said body, a second member rotatably carried on said body and-interconnected with said last chasers for'moving them into and out of, operative positio'ns'a first sector mounted on said first movable member and having notches formed therein, one notch for each operative'position of said first set of chasers', a second sector mounted onsaid second movable member and normally in advance of the other 'se ct on'said second sector also havingnotehes formed therein one for each operative po'sition 'of said seco'nd set of chasers; a lever mounted on said; body; a pawl carried by said lever comments th'enbtches in both said sectors, whereby'eith'er of said. sets of chasers may be set and locked inoperative positions by the engagement of sai'd'pawl with a notch in either of said sectors, I, I II 5. In a die head, abody, asetof chasers movably supported therein, a memberrotatably carried on said body and interconnected with said chasers' for moving them into and out of operative' positions; a second set of chaser's movably supported in said body, a secondmember rotatably carried on said body and inter'connejctedwith said last chasers for moving them into and out of operative positions, a' fir stj sector mounted on said first movable memberandj having notches formed therein, one notch foreach operative position of said first set of chasers a second sector mounted on said secondjmovable member and normally in advance of the' other sector,

said second sector also having notches fo'rmed therein one for each operative position of' said secondrset of chasers, a lever pivotally mounted on said body, a pawl carried by saidlever common to the notches in both saidsect'ors', whereby either of said sets of chas'er's" may be set and locked in operative positions I by the engagement of said pawl with a notch in' either of said sectors, automatic work controlledniansfor ac- 3 tuating' said lever to disengage sanpawrrrom a notch with'which it is engaged, and means op perativeon the disengagement of said pawl for causing the member interconnected with, the chasers in the operative" position for moving them to an inoperativeposition II I 6. In a diehead, a body, -a setofc asersrnovably supported therein; e be rota abl r-- ried on said bodyand interconnected with said sh' o moving them in and out o pe ative'positions, a second set oi chasers movably supported in said body, a second member rotatably carried on said body and intercomf ected with said last chasers for moving them into and out of operative positions, a .first sector mounted on s aid first movable memberand having notches formed therein, one notch ,foreach operative position of said first 'set of chasers,';a second sector mounted on said second movable member and normally in advance of thelotherj secto'r said second sector alsohaving notches formed there'- in onefor each operative position ofsaidsecand set of chasers, a lever'pivotally' mounted on said body, a pawl? carried by said'lever common ;,to the notches in' both said sector's, whereby either of said sets of chasers'may be setan'd locked in operative positions by the enga e ment of said pawl with a notch'in'either' of said sectors, a depressible: plunger mounted in saidbody, means actuating-upon said'plun'ger for biasing the latter to a raised "position, work releasable latching meansfor holding 's'aid'plunger'in a depressed position, and a' stiidmounted on said plunger and moved by said plunger along a path spanned bysaidievenand: adapted when said plunger is released to operate s aid'levIer of said notches, said Studbeing plunger to a position awayfr I I I enabling movement of said; lever to engage said pawl with oneof said hbtche'sf witli'ifiit "efie'ctin'g ii-the depression ofsaid**plungci 7. In a die head, a body, a set of chasers 'movably supported therein, a member rotatably carried on said body and interconnected with said chasers for moving them into and out of op erative positions, a second set of chasers movably supported in said body, a second member rotatably carried on said body and interconnected with said last chasers for moving them into and out of operative positions, a first sector mounted on said first movable member and having notches formed therein, one notch for each operative position of said first set of chasers, a second sector mounted on said second movable member and normally in advance of the other sector, said second sector also having notches formed therein one for each operative position of said second set of chasers, a lever pivotally mounted on said body, a pawl carried by said lever common to the notches in both said sectors, a depressible plunger mounted in said body, said lever being movable to engage said pawl with one of said notches when said plunger is depressed, a finger pivotally carried by the inner end of said plunger and adapted to be positioned in the path of the Work for actuation thereby when said plunger is depressed, latching means engageable with said finger to hold said plunger in a depressed position, means for moving said plunger to a raised position when said finger is deactuated by said work to disengage said latch, means carried by said plunger for actuating said lever on the raising of said plunger to unlock the member interconnected with the set of chasers in the operative position, and means for actuating said last member to move the chasers from the operative position to an inoperative position.

8. In a die head, a body, a set of chasers movably suported therein, a member rotatably carried on said body and interconnected with said chasers for moving them into and out of operative positions, a second set of chasers movably supported in said body, a second member rotatably carried on said body and interconnected with said last chasers for moving them in and out of operative positions, complementary locking means carried in part on said body and in part on said members for locking either of the latter to retain the set of chasers interconnected therewith in operative positions, a depressible plunger mounted in said body and movable radially therein, means carried on said plunger and adapted to unlock said locking means, a pivoted finger carried on the inner end of said plunger and adapted to be positioned in the path of the work when said plunger is depressed, a latching pin engageable with said finger to hold said plunger in a depressed position, said finger being adapted to be disengaged from said pin by the work, and means acting upon said plunger for moving it to the raised position for effecting the unlocking of said locking means.

9. In a die head, a body, a set of thread chasers movably supported therein, a die plate rotatably carried on said body and having follow cams thereon engaging said chasers for moving them into and out of operative positions, a second set of chasers movably supported in said body, a second cam plate rotatably carried on said body and having follow cams therein engaging said last chasers for moving them in and out of operative positions, a depressible plunger mounted in said body and movable radially therein, a stud carried by said plunger, a first sector mounted on said first cam plate and having notches formed therein corresponding to said first operative positions, a second sector mounted on said second cam plate and normally in advance of said first sector, said second sector also having notches formed therein corresponding to said second operative positions, a lever mounted on said body, a pawl carried by said lever and common to both said sectors and engageable with'the notches of either of said sectors for locking either set of chasers in an operative position, a depressible plunger mounted in said body, a stud carried by said plunger for operating said lever to release said pawl from engagement with one of said notches, a pivoted finger carried by said plunger and adapted to be positioned in the path of Work when said plunger is depressed, latching means cooperating with said finger to lock said plunger in a depressed position, said finger being adapted to be unlatched by the worl: on the completion of a working operation, means operative upon the unlatching of said finger to actuate said plunger for causing disengagement of the pawl from the notch with which it is engaged and spring means connected with said body and with said cam plates for actuating either one of them i to move the set of chasers controlled thereby to an inoperative position.

10. In a die head, a body, a set of chasers thereon, means including a member movable on said body for moving said chasers into and out of operative positions, a second set of chasers in said body, means including a second member movable relative to said body for moving said second set of chasers into and out of operative position, a pawl carried by said body, a notched sector mounted on and movable with said first member, and a second notched sector mounted on and movable with said second member, whereby either of said sets of chasers may be set and locked in a selected operative position by engaging said pawl with one of the notches on either of said sectors.

11. In a die head, a body, a set of chasers thereon, means including a member movable on said body for moving said chasers into and out of operative positions, a second set of chasers in said body, means including a second member movable relative to said body for moving said second set of chasers into and out of operative position, a pawl carried by said body, a notched sector mounted on and movable with said first member, a second notched sector mounted on and movable with said second member, whereby either of said sets of chasers may be set and locked in a selected operative position by engaging said pawl with one of the notches on either of said sectors, and camming means carried by at least one of said members for disengaging said pawl from a notch in the sector on the other of said members, when the latter had been previously set for an operation, thereby releasing its set of chasers and permitting the other set of chasers controlled by said one of said members to be set and locked for a different operation.

12. In a die head, a body, a set of chasers thereon, means including a member movable on said body for moving said chasers into and out of operative positions, a second set of chasers in said body, means including a second member movable relative to said body for moving said second set of chasers into and out of operative position, a, pawl carried by said body, a notched sector mounted on and movable with said first member, a second notched sector mounted on and movable with said second member, whereby either of said sets; of chasers may be, set'andlockedin a selected operative position by engaging said pawl with one of the notches on either of said sectors, and means carried on said body for performing initial operations on the end of the work for facilitating a thread chasing operation thereon.

13. A die head according to claim 4, in which adjustable means is provided between-said body and said pawl, operating through said notched sectors, and connections between said rotatable members and the chasers controlled thereby to produce appropriate settings of said chasers for corresponding sizes of pipe threads.

14. A die head according to claim 4, in which at least one of said sectors is adjustably mounted on its rotatable member whereby said sector may be set and secured with any one of its notches in engagement with said pawl to insure that the corresponding setting of the chasers controlled by said last member produces the correct thread size indicated for the notch engaged by said pawl,

15. A die head according to claim 4, in which said first sector is fixed on said first mentioned member and said second sector is adjustably carried on said second member, adjustable and lockable means being provided between said body and the lever supporting said pawl, whereby said adjustable and lockable means is employed to correctly set the pawl to control the position of said first sector and its notches, thereby correctly positioning the die set which it controls.

16. A die head according to claim 4, in which the second of said sectors is adjustably mounted on its rotatablemember. whereby the same may be adjusted on its rotatable member to efiect:

correct settings of said second set of chasers, so that after said sector has been properly adjusted with the pawl in any one of its notches to correctly position said second set of chasers for cutting the correspondin size of pipe thread, it may be locked so that thereafter setting the pawl in any of the notches of that sector sets the chasers for the corresponding size of pipe thread cutting.

17. A die head according to claim 4, in which said'first sector is fixed on said first mentioned member and said second sector is adjustably mounted on said second member, adjustable and lockable means beingprovided between said body and said pawl, whereby said adjustable and lockable means is employed to set the pawl to control the notches in said sectors so that the die set controlled by the first sector, its rotatable member and inner connections thereof, will be correctly positioned for cutting thread sizes corresponding to its several notches, while the second sector being adjustably mounted on the second rotatable member is then so adjusted and set as to similarly control the secondset of dies for the several settings requiredof them for the cutting of corresponding sizes of pipe threads.

. JAMES I-IERV'EYHSTERNBERGH.

No references cited. 

